This invention relates to a fluid coupling device which joins and provides an effective seal between upstream and downstream conduits, which device is flexible in that it permits angular misalignment, axial movement and rotation of a body portion of the device relative to the adjoining conduits.
Such devices, broadly speaking, are old and well known in the prior art. See, for example, the sealing apparatus disclosed in U.S. Pat. No. 4,054,306 issued to B. J. Sadoff, Jr. et al. on Oct. 18, 1977. In one disclosed example, the reference apparatus includes an end ring portion joined to a frustoconical tapered portion, which is, in turn, joined to a frustoconical short portion, joined in turn to a cylindrical portion. Each of these portions are hollow and are integrally joined to one another and, in addition, the cylindrical portion is welded to the end of a first fluid conduit. The end ring portion, tapered portion and short portion fit within a bore in a body member, which bore forms an adjoining second fluid conduit. The ring portion is crowned in that its periphery is convex and arcuate in longitudinal cross-section and is slightly oversized compared to the diameter of the bore so as to be spring loaded against and around the bore defining wall to form a fluid seal. The reference apparatus is capable of angular misalignment relative to the longitudinal centerline of the bore as well as capable of longitudinal and rotational sliding movement within the bore while providing a fluid path between the first and second conduits.
A difficulty that has been encountered using this type of prior art coupling is that, over relative short time periods, due to vibraton and rubbing movement of the ring portion against the bore wall, the crown of the ring portion begins to wear thus resulting in fluid leakage between the crown and bore wall interface. Consequently the single ring portion of the reference assembly does not provide an effective fluid seal over a long duration, even when the assembly is used in a relatively low pressure fluid environment. Moreover, because the end ring portion of the reference device is integral with the other component parts thereof, the end ring portion can not be replaced without replacing the entire device. Consequently, the entire device must be discarded when the end ring portion sustains excessive wear which, unfortunately, occurs in relatively short order as previously indicated.
By means of the present invention, these and other difficulties encountered with prior art flexible couplings for transferring fluids between conduits and for providing an effective fluid seal therebetween is substantially overcome.